You don't say how old your kids are, judging by the activities you list, I guess toddler to pre-school age?
We had one of those play kitchens and my kids would cook along with me, me at my stove and they at theirs. As they got a little bit older, they could help me with some tasks, stirring was always a big hit, helping set the table, help me taste the food (my son was really good at that, and it gets them invested at eating it at the table, too ;-))
have the older one "read" to the younger one(s) - they usually have their favorite books memorized
playing with their train tracks
Playing with wooden blocks
pushing cars around the floor, with obstacle courses around table and chair legs (can you tell I have boys? LOL)
play them a story CD or tape, so they can sit and listen (instead of watching moving pictures they get to make them in their own head; and no commercials) - I love the story tapes recorded by Jim Weiss and so did my boys
crayons and blank paper (not a coloring book)
construction paper and kid-safe blunt scissors and crayons
sing the clean-up song with them and have them pick up the toys they played with earlier, in preparation for dinner and the evening (my kids did that really well when it was also timed, they were competitive and tried to beat their own time)
empty the dryer and have them sort socks; they can also start to fold laundry, at least socks and underwear...
when they were younger:
have them "sort" tupperware container lids
build towers with or stack old yogurt containers and similar
play drums with a pot and wooden spoon
sing songs together
recite nursery rhymes while they do the movements that go with them
make pictures with our special refrigerator magnets (they were different shapes and colors, people, cars, sun, houses, dogs, etc, so you could make real pictures and tell a story to go along with it, or rather they would tell me the story to go with it)